1. Field of the Invention
The present invention relates to ball valves useful in the medical industry for installation in either an intravenous bag, intravenous line or a dosage meter.
2. Description of the Prior Art
During hospitalization, a patient's body fluids must be replenished by infusion in order to maintain certain levels of body fluids. The nurse must monitor the addition of body fluids such as Ringer's Solution, blood plasma, sucrose solution, glucose solution, saline solution, etc., in order to prevent the entrapment of air in the solutions when the supply of infusion fluid is exhausted. When air is allowed to enter the patient's blood stream as air emboli, serious conditions such as infarction of the heart and/or brain may result. Therefore, the present inventor has devised a simplified ball valve system to enable hospital personnel to observe the depletion of the infusion fluid and prevent such problems. When the fluid is about to be exhausted, this invention would automatically cut-off the fluid supply, thereby preventing entrapment of air in the body fluid being infused. No complicated machinery is required as disclosed by the following prior art.
Examples of complicated intravenous infusion control devices are illustrated by the following patents. In U.S. Pat. Nos. 4,551,134 and 4,525,163, issued on Nov. 5, 1985 and Jun. 25, 1985, respectively, to William H. Slavik et al., a magnetically responsive ball is displaced from its fluid stopping position by an electromagnet programmed by a micro-computer to initiate a drip-dropping schedule.
In U.S. Pat. No. 4,519,792 issued on May 28, 1985, to Garfield A. Dawe, an infusion pump system contains a removable cassette including two magnetically biased valves at each end with externally mounted magnets monitored within prescribed pressure limits by a micro-computer to control fluid flow.
In U.S. Pat. No. 4,038,981 to Robert J. LeFevre et al. and U.S. Pat. No. 4,038,982 to George K. Burke et al., both issued on Aug. 2, 1977, an electronically controlled, gravity-feed, intravenous infusion set which controls drops of fluid by dislodging a ball of unknown composition by either an electromagnet or a permanent magnet is disclosed. An essential component of this system is a computerized photometric system which controls the drop frequency.
In U.S. Pat. No. 4,037,596 issued on Jul. 26, 1977, to Robert J. LeFevre et al., a drop by drop parenteral administration set with an internal valve containing a steel ball and a flow restrictor which limits and actuates the ball valve is disclosed. No magnetic control is contemplated.
In U.S. Pat. No. 4,103,686 issued on Aug. 1, 1978 to Robert J. LeFevre, a dual valve assembly for dual intravenous infusions for controlling both forward and reverse flow through a flow line is disclosed. The valve ball is controlled by an external electromagnet (and a drop frequency controller) which when energized displaces the valve ball from its closing position. The second valve member is a disc which normally closes off the gravity fed fluid, and the disc is dislodged by energizing the valve ball to move it and a third fluted actuating rod to push up the disc and commence feeding of the fluid.
Finally, U.S. Pat. No. 4,708,831 issued on Nov. 24, 1987 to Adrian J. Elsworth et al. discloses a water humidifier which dispenses water through a removable drop counter containing a magnetically actuated steel ball valve. The electromagnet is controlled by a micro-processor to displace the steel ball slightly from its closing position and permit water flow.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.